About Tonsillectomy
Tonsillectomy is one of the most commonly performed surgical procedures in the United States with approximately 400,000 operations conducted per year. The tonsils are masses of lymphoid tissue that are embedded in the lateral wall of the pharynx or throat. They are large in the younger years but progressively atrophy as the patient ages. Tonsillectomy is the surgical procedure performed typically under general anesthesia in which the tonsils are removed from the patient's throat in order to treat a disease state involving the tonsils.
Indications for Tonsillectomy
The two disease processes that most commonly affect the tonsils and provide the indications for tonsillectomy are chronic tonsillitis and tonsillar hypertrophy. Chronic tonsillitis occurs when bacteria is retained in or trapped by tonsillar tissue and this leads to chronic infection which eventually becomes unresponsive to medical therapy using antibiotics. When the frequency of infection becomes excessive, physical removal of the tonsillar reservoir of infection becomes necessary. Tonsillar hypertrophy or the development of excessively large tonsils leads to obstructive breathing problems and airway obstruction and is associated with sleep apnea. Tonsillectomy is most commonly performed in the pediatric population but is also performed on adults—most commonly for chronic tonsillitis.
Anatomy
The tonsils lie bilaterally on the lateral walls of the throat in a pocket created between two folds of the soft palate known as the anterior and posterior pillars of the tonsil. The soft palate consists of mucous membrane lining underneath, which is a layer of muscle. The tonsils themselves lie in this pocket and sit on a bed of muscle.
Tonsillectomy Procedure
The tonsillectomy procedure may be thought of in two stages. In the exposure stage, the tonsil is exposed by cutting through overlying mucous membrane and muscle tissue that conceals the tonsil. In the dissection stage, the tonsil itself is separated free from the underlying muscle bed and removed. In the first stage, the tonsil is grasped with a forceps and retracted towards the midline of the throat. A cut is made in the superior pole of the tonsil through the mucous membrane of the anterior tonsillar pillar. Next, the muscular layer below is divided until the proper tissue plane is reached. These mucous membrane and muscle cuts are made with a sharp instrument, such as a needle-tipped electrocautery unit. Next, dissection is carried inferiorly separating the tonsil tissue from the underlying muscle until the inferior pole of the tonsils is reached and transacted. This phase requires blunt dissection with a pushing motion as the tonsil may be “peeled” away from the underlying tissue. Identifying and staying within the confines of this dissection plane is crucial for a variety of reasons. First, maintenance of a proper plane of dissection minimizes injury to and tearing of the underlying muscular layer. This minimizes bleeding thereby reducing the need for electrocautery and thereby reducing post operative pain. During this stage, numerous perforating blood vessels are encounted which must be well-cauterized in order to avoid intra-operative and post-operative bleeding. Intra-operative bleeding obscures the surgical field and post-operatibe bleeding forces a return of the patient to the operating room for control of hemorrhage. Most commonly, two instruments are used to perform tonsillectomy. In the first or exposure stage a sharp needle-tipped electrocautery is used to expose the tonsil. In the second or dissection stage, a suction-electrocautery is used to control bleeding.
A variety of tools for tonsillectomy have been developed over the years including sharp instruments such as scalpels, electro-cautery units, lasers. The most commonly used tool is the electro-cautery unit.
The goals of an ideal tonsillectomy technique include the following: minimization of bleeding and minimization of post-operative pain and minimization of operative time. Minimization of bleeding during the procedure is important to improve visualization of the surgeon and to control patient blood loss especially in younger children. Minimization of post operative pain improves patient comfort and reduces the amount of time-off for both patients and caregiver parents of children. Dehydration is a common complication following tonsillectomy and is related to post operative pain on swallowing. Minimization of operative time maximizes efficient use of operating room time and reduce the amount of time patients are subjected to general anesthesia. It is well accepted that postoperative pain is minimized with minimal exposure of tissue to electrocautery. Therefore any technique that limits or reduces the amount of electrocautery applied can be expected to cause less post-operative pain.
An existing public domain device (PDD) is manufactured by A&E a New Jersey corporation that is owned by Alto Medical Corporation. One such PDD device is depicted in prior art FIGS. 1, 6, 8, 11, and 13. Specifically, a PDD suction coagulator 10 is shown. That device provides a handle assembly 12, a handle grip 14, and a cannula 16. The cannula 16 comprises an insulation layer 18 and a tip 20 at the distal end 22 of the cannula 16. In addition, the handle assembly 12 is provided with a suction port 24 and an electrical cord 26. This device operates by connecting a suction tube to suction port 24 and an electrical power to electrical cord 26. Electrical cord 26 connects through the handle assembly to a metal chamber inside cannula 16 that connects to cauterizing tip 20. Accordingly, tip 20 is used for dissection. In addition, suction may be applied through suction port 24 in an attempt to suck liquids or other materials at the dissection or cauterizing area.
As shown in FIG. 6, tip 20 may comprise a tab end 28 that terminates at a convex portion 30 which is connected to an intake portion 32. As FIGS. 6, 8, 11, and 13 illustrate, the PDD metal tip is designed for dissection but has many problems with respect to cauterizing and suction. Indeed, there are many problems with the PDD. First, with respect to tip shape and angulation, the PDD metal tip is a broad, round, long, widely curved and somewhat flimsy metal tab which makes blunt dissection unrewarding and is not pointed enough for precise dissection. The tip does not provide adequate current density to allow pinpoint cutting. The PDD tip is not well suited for blunt dissection.
In addition, the PDD provides electrical insulation on the main shaft that extends the full length of the tube. Only the metal “tab” sticking out conducts current. This tab prevents proper contact of tissue with the tube lumen thereby impairing effective cautery. This leaves very little exposed metal for conductive contact with the tissue. The insulation going down the full length of the tube prevents adequate contact with the tissue being sucked into the tube.
Also, the PDD device locates the suction port on the side of the unit towards the lumen of the tube. This is ergonomically incorrect for proper thumb positioning when performing the procedure.
Other drawbacks and disadvantages exist for existing surgical devices.